Weather balloons use radio sondes that send raw GPS data to the ground. A program, such as SondeMonitor ( http://www.coaa.co.uk/sondemonitor.htm ) is used to convert the raw data to latitude, longitude and altitude. The program requires the orbital elements of the GPS satellites at the time the data was measure. The orbital elements can be downloaded from a website, or they can be imported from a GPS unit connected to the computer.

We recorded the raw data on tens of thousands of GPS readings and then sent the data on a flash card out to be processed so that method can work. Got the results back in two weeks but it worked and with greater confidence on altitude position than a .regular commercial type receiver/altimeter even though there have been amateur rocket attempts that have successfully had GPS lock above 100,000'.

Raw data and pre processed data are two different things. Recording the signals from the front end of the GPS will give you data you wont get with RAW GPS data and post processed it wont have the COCOM limits inposed on RAW data.The radiosonde's process front end data not RAW GPS data so that signal is what you want. There is no GPS in the sonde at all it just transmitts the front end signal and it's processed on the ground. So no COCOM limits. Interesting huh : )

Indeed. Really enjoyed the write-up as well. Although strictly speaking I'm not sure it's "suitable for being published in a magazine" . But I'd say it's a case of above and beyond, and they won the prize fair and square! Congratulations!

_________________Say, can you feel the thunder in the air? Just like the moment ’fore it hits – then it’s everywhereWhat is this spell we’re under, do you care? The might to rise above it is now within your sphereMachinae Supremacy – Sid Icarus